diff --git a/gprofng/libcollector/collector.c b/gprofng/libcollector/collector.c
index eb192647007..3d8e48d4ea3 100644
--- a/gprofng/libcollector/collector.c
+++ b/gprofng/libcollector/collector.c
@@ -1578,7 +1578,7 @@ __collector_resume_experiment ()
 }
 
 /* Code to support Samples and Pause/Resume */
-void collector_sample () __attribute__ ((weak, alias ("__collector_sample")));
+void collector_sample (char *name) __attribute__ ((weak, alias ("__collector_sample")));
 void
 __collector_sample (char *name)
 {
diff --git a/gprofng/libcollector/dispatcher.c b/gprofng/libcollector/dispatcher.c
index f7cd46e7e6b..4eda18ec324 100644
--- a/gprofng/libcollector/dispatcher.c
+++ b/gprofng/libcollector/dispatcher.c
@@ -1281,4 +1281,3 @@ __collector_ext_clone_pthread (int (*fn)(void *), void *child_stack, int flags,
 int sigprocmask (int, const sigset_t*, sigset_t*) __attribute__ ((weak, alias ("__collector_sigprocmask")));
 int thr_sigsetmask (int, const sigset_t*, sigset_t*) __attribute__ ((weak, alias ("__collector_thr_sigsetmask")));
 int setitimer () __attribute__ ((weak, alias ("_setitimer")));
-
diff --git a/gprofng/libcollector/envmgmt.c b/gprofng/libcollector/envmgmt.c
index a399c0d0cb4..f2bf2c41bfb 100644
--- a/gprofng/libcollector/envmgmt.c
+++ b/gprofng/libcollector/envmgmt.c
@@ -685,8 +685,8 @@ __collector_env_update (char *envp[])
 
 
 /*------------------------------------------------------------- putenv */
-int putenv () __attribute__ ((weak, alias ("__collector_putenv")));
-int _putenv () __attribute__ ((weak, alias ("__collector_putenv")));
+int putenv (char*) __attribute__ ((weak, alias ("__collector_putenv")));
+int _putenv (char*) __attribute__ ((weak, alias ("__collector_putenv")));
 
 int
 __collector_putenv (char * string)
@@ -694,9 +694,9 @@ __collector_putenv (char * string)
   if (CALL_UTIL (putenv) == __collector_putenv ||
       CALL_UTIL (putenv) == NULL)
     { // __collector_libc_funcs_init failed
-      CALL_UTIL (putenv) = (int(*)())dlsym (RTLD_NEXT, "putenv");
+      CALL_UTIL (putenv) = (int(*)(char*))dlsym (RTLD_NEXT, "putenv");
       if (CALL_UTIL (putenv) == NULL || CALL_UTIL (putenv) == __collector_putenv)
-	  CALL_UTIL (putenv) = (int(*)())dlsym (RTLD_DEFAULT, "putenv");
+	  CALL_UTIL (putenv) = (int(*)(char*))dlsym (RTLD_DEFAULT, "putenv");
       if (CALL_UTIL (putenv) == NULL || CALL_UTIL (putenv) == __collector_putenv)
 	{
 	  TprintfT (DBG_LT2, "__collector_putenv(): ERROR: no pointer found.\n");
@@ -712,8 +712,8 @@ __collector_putenv (char * string)
 }
 
 /*------------------------------------------------------------- setenv */
-int setenv () __attribute__ ((weak, alias ("__collector_setenv")));
-int _setenv () __attribute__ ((weak, alias ("__collector_setenv")));
+int setenv (const char*, const char*, int) __attribute__ ((weak, alias ("__collector_setenv")));
+int _setenv (const char*, const char*, int) __attribute__ ((weak, alias ("__collector_setenv")));
 
 int
 __collector_setenv (const char *name, const char *value, int overwrite)
@@ -721,9 +721,9 @@ __collector_setenv (const char *name, const char *value, int overwrite)
   if (CALL_UTIL (setenv) == __collector_setenv ||
       CALL_UTIL (setenv) == NULL)
     { // __collector_libc_funcs_init failed
-      CALL_UTIL (setenv) = (int(*)())dlsym (RTLD_NEXT, "setenv");
+      CALL_UTIL (setenv) = (int(*)(const char*, const char*, int))dlsym (RTLD_NEXT, "setenv");
       if (CALL_UTIL (setenv) == NULL || CALL_UTIL (setenv) == __collector_setenv)
-	CALL_UTIL (setenv) = (int(*)())dlsym (RTLD_DEFAULT, "setenv");
+	CALL_UTIL (setenv) = (int(*)(const char*, const char*, int))dlsym (RTLD_DEFAULT, "setenv");
       if (CALL_UTIL (setenv) == NULL || CALL_UTIL (setenv) == __collector_setenv)
 	{
 	  TprintfT (DBG_LT2, "__collector_setenv(): ERROR: no pointer found.\n");
@@ -758,8 +758,8 @@ __collector_setenv (const char *name, const char *value, int overwrite)
 }
 
 /*------------------------------------------------------------- unsetenv */
-int unsetenv () __attribute__ ((weak, alias ("__collector_unsetenv")));
-int _unsetenv () __attribute__ ((weak, alias ("__collector_unsetenv")));
+int unsetenv (const char*) __attribute__ ((weak, alias ("__collector_unsetenv")));
+int _unsetenv (const char*) __attribute__ ((weak, alias ("__collector_unsetenv")));
 
 int
 __collector_unsetenv (const char *name)
@@ -767,9 +767,9 @@ __collector_unsetenv (const char *name)
   if (CALL_UTIL (unsetenv) == __collector_unsetenv ||
       CALL_UTIL (unsetenv) == NULL)
     { // __collector_libc_funcs_init failed
-      CALL_UTIL (unsetenv) = (int(*)())dlsym (RTLD_NEXT, "unsetenv");
+      CALL_UTIL (unsetenv) = (int(*)(const char*))dlsym (RTLD_NEXT, "unsetenv");
       if (CALL_UTIL (unsetenv) == NULL || CALL_UTIL (unsetenv) == __collector_unsetenv)
-	CALL_UTIL (unsetenv) = (int(*)())dlsym (RTLD_DEFAULT, "unsetenv");
+	CALL_UTIL (unsetenv) = (int(*)(const char*))dlsym (RTLD_DEFAULT, "unsetenv");
       if (CALL_UTIL (unsetenv) == NULL || CALL_UTIL (unsetenv) == __collector_unsetenv)
 	{
 	  TprintfT (DBG_LT2, "__collector_unsetenv(): ERROR: no pointer found.\n");
diff --git a/gprofng/libcollector/jprofile.c b/gprofng/libcollector/jprofile.c
index cd498bed0a3..d8f2d049a84 100644
--- a/gprofng/libcollector/jprofile.c
+++ b/gprofng/libcollector/jprofile.c
@@ -99,8 +99,8 @@ static void rwrite (int fd, const void *buf, size_t nbyte);
 static void addToDynamicArchive (const char* name, const unsigned char* class_data, int class_data_len);
 static void (*AsyncGetCallTrace)(JVMPI_CallTrace*, jint, ucontext_t*) = NULL;
 static void (*collector_heap_record)(int, int, void*) = NULL;
-static void (*collector_jsync_begin)() = NULL;
-static void (*collector_jsync_end)(hrtime_t, void *) = NULL;
+static void (*collector_jsync_begin)(void) = NULL;
+static void (*collector_jsync_end)(hrtime_t, void*) = NULL;
 
 #define gethrtime collector_interface->getHiResTime
 
@@ -224,7 +224,7 @@ open_experiment (const char *exp)
       else if (__collector_strStartWith (args, "s:") == 0)
 	{
 	  java_sync_mode = 1;
-	  collector_jsync_begin = (void(*)(hrtime_t, void *))dlsym (RTLD_DEFAULT, "__collector_jsync_begin");
+	  collector_jsync_begin = (void(*)(void))dlsym (RTLD_DEFAULT, "__collector_jsync_begin");
 	  collector_jsync_end = (void(*)(hrtime_t, void *))dlsym (RTLD_DEFAULT, "__collector_jsync_end");
 	}
 #endif
@@ -249,7 +249,7 @@ __collector_jprofile_enable_synctrace ()
       return;
     }
   java_sync_mode = 1;
-  collector_jsync_begin = (void(*)(hrtime_t, void *))dlsym (RTLD_DEFAULT, "__collector_jsync_begin");
+  collector_jsync_begin = (void(*)(void))dlsym (RTLD_DEFAULT, "__collector_jsync_begin");
   collector_jsync_end = (void(*)(hrtime_t, void *))dlsym (RTLD_DEFAULT, "__collector_jsync_end");
   TprintfT (DBG_LT1, "jprofile: turning on Java synctrace, and requesting events\n");
 }
@@ -1123,7 +1123,7 @@ jprof_find_asyncgetcalltrace ()
 {
   void *jvmhandle;
   if (__collector_VM_ReadByteInstruction == NULL)
-    __collector_VM_ReadByteInstruction = (int(*)()) dlsym (RTLD_DEFAULT, "Async_VM_ReadByteInstruction");
+    __collector_VM_ReadByteInstruction = (int(*)(unsigned char*)) dlsym (RTLD_DEFAULT, "Async_VM_ReadByteInstruction");
 
   /* look for stack unwind function using default path */
   AsyncGetCallTrace = (void (*)(JVMPI_CallTrace*, jint, ucontext_t*))
diff --git a/gprofng/libcollector/libcol_util.c b/gprofng/libcollector/libcol_util.c
index baac15db5c4..a73488e3f60 100644
--- a/gprofng/libcollector/libcol_util.c
+++ b/gprofng/libcollector/libcol_util.c
@@ -1114,7 +1114,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "munmap");
   if (ptr)
-    __collector_util_funcs.munmap = (int(*)())ptr;
+    __collector_util_funcs.munmap = (int(*)(void *, size_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT munmap: %s\n", dlerror ());
@@ -1123,7 +1123,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "close");
   if (ptr)
-    __collector_util_funcs.close = (int(*)())ptr;
+    __collector_util_funcs.close = (int(*)(int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT close: %s\n", dlerror ());
@@ -1158,7 +1158,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "close");
   if (ptr)
-    __collector_util_funcs.close = (int(*)())ptr;
+    __collector_util_funcs.close = (int(*)(int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT close: %s\n", dlerror ());
@@ -1167,7 +1167,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "read");
   if (ptr)
-    __collector_util_funcs.read = (ssize_t (*)())ptr;
+    __collector_util_funcs.read = (ssize_t (*)(int, void*, size_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT read: %s\n", dlerror ());
@@ -1176,7 +1176,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "write");
   if (ptr)
-    __collector_util_funcs.write = (ssize_t (*)())ptr;
+    __collector_util_funcs.write = (ssize_t (*)(int, void*, size_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT write: %s\n", dlerror ());
@@ -1186,14 +1186,14 @@ __collector_util_init ()
 #if ARCH(Intel) && WSIZE(32)
   ptr = dlvsym (libc, "pwrite", "GLIBC_2.2"); // it is in /lib/libpthread.so.0
   if (ptr)
-    __collector_util_funcs.pwrite = (ssize_t (*)())ptr;
+    __collector_util_funcs.pwrite = (ssize_t (*)(int, void*, size_t, off_t))ptr;
   else
     {
       Tprintf (DBG_LT0, "libcol_util: WARNING: dlvsym for %s@%s failed. Using dlsym() instead.", "pwrite", "GLIBC_2.2");
 #endif /* ARCH(Intel) && WSIZE(32) */
       ptr = dlsym (libc, "pwrite");
       if (ptr)
-	__collector_util_funcs.pwrite = (ssize_t (*)())ptr;
+	__collector_util_funcs.pwrite = (ssize_t (*)(int, const void*, size_t, off_t))ptr;
       else
 	{
 	  CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT pwrite: %s\n", dlerror ());
@@ -1213,7 +1213,7 @@ __collector_util_init ()
 #endif /* ARCH(Intel) && WSIZE(32) */
       ptr = dlsym (libc, "pwrite64");
       if (ptr)
-	__collector_util_funcs.pwrite64_ = (ssize_t (*)())ptr;
+	__collector_util_funcs.pwrite64_ = (ssize_t (*)(int, const void*, size_t, off_t))ptr;
       else
 	__collector_util_funcs.pwrite64_ = __collector_util_funcs.pwrite;
 #if ARCH(Intel) && WSIZE(32)
@@ -1222,7 +1222,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "lseek");
   if (ptr)
-    __collector_util_funcs.lseek = (off_t (*)())ptr;
+    __collector_util_funcs.lseek = (off_t (*)(int, off_t, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT lseek: %s\n", dlerror ());
@@ -1231,7 +1231,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "access");
   if (ptr)
-    __collector_util_funcs.access = (int(*)())ptr;
+    __collector_util_funcs.access = (int(*)(const char*, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT access: %s\n", dlerror ());
@@ -1240,7 +1240,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "mkdir");
   if (ptr)
-    __collector_util_funcs.mkdir = (int(*)())ptr;
+    __collector_util_funcs.mkdir = (int(*)(const char*, mode_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT mkdir: %s\n", dlerror ());
@@ -1249,7 +1249,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "opendir");
   if (ptr)
-    __collector_util_funcs.opendir = (DIR * (*)())ptr;
+    __collector_util_funcs.opendir = (DIR * (*)(const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT opendir: %s\n", dlerror ());
@@ -1258,7 +1258,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "closedir");
   if (ptr)
-    __collector_util_funcs.closedir = (int(*)())ptr;
+    __collector_util_funcs.closedir = (int(*)(DIR*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT closedir: %s\n", dlerror ());
@@ -1267,7 +1267,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "execv");
   if (ptr)
-    __collector_util_funcs.execv = (int(*)())ptr;
+    __collector_util_funcs.execv = (int(*)(const char*, char* const*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT execv: %s\n", dlerror ());
@@ -1276,7 +1276,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "exit");
   if (ptr)
-    __collector_util_funcs.exit = (void(*)())ptr;
+    __collector_util_funcs.exit = (void(*)(int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT exit: %s\n", dlerror ());
@@ -1285,7 +1285,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "vfork");
   if (ptr)
-    __collector_util_funcs.vfork = (pid_t (*)())ptr;
+    __collector_util_funcs.vfork = (pid_t (*)(void))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT vfork: %s\n", dlerror ());
@@ -1294,7 +1294,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "waitpid");
   if (ptr)
-    __collector_util_funcs.waitpid = (pid_t (*)())ptr;
+    __collector_util_funcs.waitpid = (pid_t (*)(pid_t, int*, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT waitpid: %s\n", dlerror ());
@@ -1313,7 +1313,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "getcontext");
   if (ptr)
-    __collector_util_funcs.getcontext = (int(*)())ptr;
+    __collector_util_funcs.getcontext = (int(*)(ucontext_t*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT getcontext: %s\n", dlerror ());
@@ -1331,7 +1331,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "putenv");
   if (ptr)
-    __collector_util_funcs.putenv = (int(*)())ptr;
+    __collector_util_funcs.putenv = (int(*)(char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT putenv: %s\n", dlerror ());
@@ -1340,7 +1340,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "getenv");
   if (ptr)
-    __collector_util_funcs.getenv = (char*(*)())ptr;
+    __collector_util_funcs.getenv = (char*(*)(const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT getenv: %s\n", dlerror ());
@@ -1349,7 +1349,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "time");
   if (ptr)
-    __collector_util_funcs.time = (time_t (*)())ptr;
+    __collector_util_funcs.time = (time_t (*)(time_t*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT time: %s\n", dlerror ());
@@ -1358,7 +1358,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "mktime");
   if (ptr)
-    __collector_util_funcs.mktime = (time_t (*)())ptr;
+    __collector_util_funcs.mktime = (time_t (*)(struct tm*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT mktime: %s\n", dlerror ());
@@ -1372,7 +1372,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "gmtime_r");
   if (ptr)
-    __collector_util_funcs.gmtime_r = (struct tm * (*)())ptr;
+    __collector_util_funcs.gmtime_r = (struct tm * (*)(const time_t*, struct tm*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT gmtime_r: %s\n", dlerror ());
@@ -1381,7 +1381,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strtol");
   if (ptr)
-    __collector_util_funcs.strtol = (long (*)())ptr;
+    __collector_util_funcs.strtol = (long (*)(const char*, char**, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strtol: %s\n", dlerror ());
@@ -1390,7 +1390,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strtoll");
   if (ptr)
-    __collector_util_funcs.strtoll = (long long (*)())ptr;
+    __collector_util_funcs.strtoll = (long long (*)(const char*, char**, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strtoll: %s\n", dlerror ());
@@ -1402,7 +1402,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "setenv");
   if (ptr)
-    __collector_util_funcs.setenv = (int(*)())ptr;
+    __collector_util_funcs.setenv = (int(*)(const char*, const char*, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT setenv: %s\n", dlerror ());
@@ -1411,7 +1411,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "unsetenv");
   if (ptr)
-    __collector_util_funcs.unsetenv = (int(*)())ptr;
+    __collector_util_funcs.unsetenv = (int(*)(const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT unsetenv: %s\n", dlerror ());
@@ -1507,7 +1507,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "pclose");
   if (ptr)
-    __collector_util_funcs.pclose = (int(*)())ptr;
+    __collector_util_funcs.pclose = (int(*)(FILE*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT pclose: %s\n", dlerror ());
@@ -1516,7 +1516,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "fgets");
   if (ptr)
-    __collector_util_funcs.fgets = (char*(*)())ptr;
+    __collector_util_funcs.fgets = (char*(*)(char*, int, FILE*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT fgets: %s\n", dlerror ());
@@ -1543,7 +1543,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "vsnprintf");
   if (ptr)
-    __collector_util_funcs.vsnprintf = (int(*)())ptr;
+    __collector_util_funcs.vsnprintf = (int(*)(char*, size_t, const char*, ...))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT vsnprintf: %s\n", dlerror ());
@@ -1552,7 +1552,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "atoi");
   if (ptr)
-    __collector_util_funcs.atoi = (int(*)())ptr;
+    __collector_util_funcs.atoi = (int(*)(const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT atoi: %s\n", dlerror ());
@@ -1561,7 +1561,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "calloc");
   if (ptr)
-    __collector_util_funcs.calloc = (void*(*)())ptr;
+    __collector_util_funcs.calloc = (void*(*)(size_t, size_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT calloc: %s\n", dlerror ());
@@ -1571,7 +1571,7 @@ __collector_util_init ()
   ptr = dlsym (libc, "free");
   if (ptr)
     {
-      __collector_util_funcs.free = (void(*)())ptr;
+      __collector_util_funcs.free = (void(*)(void*))ptr;
     }
   else
     {
@@ -1581,7 +1581,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strdup");
   if (ptr)
-    __collector_util_funcs.libc_strdup = (char*(*)())ptr;
+    __collector_util_funcs.libc_strdup = (char*(*)(const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strdup: %s\n", dlerror ());
@@ -1594,7 +1594,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strerror");
   if (ptr)
-    __collector_util_funcs.strerror = (char*(*)())ptr;
+    __collector_util_funcs.strerror = (char*(*)(int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strerror: %s\n", dlerror ());
@@ -1602,7 +1602,7 @@ __collector_util_init ()
     }
   ptr = dlsym (libc, "strerror_r");
   if (ptr)
-    __collector_util_funcs.strerror_r = (int(*)())ptr;
+    __collector_util_funcs.strerror_r = (int(*)(int, char*, size_t))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strerror_r: %s\n", dlerror ());
@@ -1610,7 +1610,7 @@ __collector_util_init ()
     }
   ptr = dlsym (libc, "strspn");
   if (ptr)
-    __collector_util_funcs.strspn = (size_t (*)())ptr;
+    __collector_util_funcs.strspn = (size_t (*)(const char*, const char*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strspn: %s\n", dlerror ());
@@ -1619,7 +1619,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strtoul");
   if (ptr)
-    __collector_util_funcs.strtoul = (unsigned long int(*)())ptr;
+    __collector_util_funcs.strtoul = (unsigned long int(*)(const char*, char**, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strtoul: %s\n", dlerror ());
@@ -1628,7 +1628,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "strtoull");
   if (ptr)
-    __collector_util_funcs.strtoull = (unsigned long long int(*)())ptr;
+    __collector_util_funcs.strtoull = (unsigned long long int(*)(const char*, char**, int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT strtoull: %s\n", dlerror ());
@@ -1673,7 +1673,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "sysconf");
   if (ptr)
-    __collector_util_funcs.sysconf = (long(*)())ptr;
+    __collector_util_funcs.sysconf = (long(*)(int))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT sysconf: %s\n", dlerror ());
@@ -1682,7 +1682,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "sigfillset");
   if (ptr)
-    __collector_util_funcs.sigfillset = (int(*)())ptr;
+    __collector_util_funcs.sigfillset = (int(*)(sigset_t*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT sigfillset: %s\n", dlerror ());
@@ -1691,7 +1691,7 @@ __collector_util_init ()
 
   ptr = dlsym (libc, "sigprocmask");
   if (ptr)
-    __collector_util_funcs.sigprocmask = (int(*)())ptr;
+    __collector_util_funcs.sigprocmask = (int(*)(int, const sigset_t*, sigset_t*))ptr;
   else
     {
       CALL_UTIL (fprintf)(stderr, "collector_util_init COL_ERROR_UTIL_INIT sigprocmask: %s\n", dlerror ());
diff --git a/gprofng/libcollector/mmaptrace.c b/gprofng/libcollector/mmaptrace.c
index f07f4d76513..2a6857ab58e 100644
--- a/gprofng/libcollector/mmaptrace.c
+++ b/gprofng/libcollector/mmaptrace.c
@@ -1209,7 +1209,7 @@ process_vsyscall_page ()
 /*
  * collector API for dynamic functions
  */
-void collector_func_load () __attribute__ ((weak, alias ("__collector_func_load")));
+void collector_func_load (char*, char*, char*, void*, int, int, DT_lineno *) __attribute__ ((weak, alias ("__collector_func_load")));
 void
 __collector_func_load (char *name, char *alias, char *sourcename,
 		       void *vaddr, int size, int lntsize, DT_lineno *lntable)
@@ -1218,7 +1218,7 @@ __collector_func_load (char *name, char *alias, char *sourcename,
 			     vaddr, size, lntsize, lntable);
 }
 
-void collector_func_unload () __attribute__ ((weak, alias ("__collector_func_unload")));
+void collector_func_unload (void *vaddr) __attribute__ ((weak, alias ("__collector_func_unload")));
 void
 __collector_func_unload (void *vaddr)
 {
diff --git a/gprofng/libcollector/unwind.c b/gprofng/libcollector/unwind.c
index 952d26205b5..d101044bc9b 100644
--- a/gprofng/libcollector/unwind.c
+++ b/gprofng/libcollector/unwind.c
@@ -421,7 +421,7 @@ __collector_ext_unwind_init (int record)
   omp_no_walk = 1;
 
   if (__collector_VM_ReadByteInstruction == NULL)
-    __collector_VM_ReadByteInstruction = (int(*)()) dlsym (RTLD_DEFAULT, "Async_VM_ReadByteInstruction");
+    __collector_VM_ReadByteInstruction = (int(*)(unsigned char*)) dlsym (RTLD_DEFAULT, "Async_VM_ReadByteInstruction");
 
 #if ARCH(SPARC)
 #if WSIZE(64)
diff --git a/gprofng/src/collector_module.h b/gprofng/src/collector_module.h
index ebcdbca561f..fd888cd58dd 100644
--- a/gprofng/src/collector_module.h
+++ b/gprofng/src/collector_module.h
@@ -110,7 +110,7 @@ typedef struct CollectorUtilFuncs
   long (*sysinfo)(int command, char *buf, long count);
   time_t (*time)(time_t *tloc);
   int (*unsetenv)(const char *name);
-  int (*vsnprintf)(char *str, size_t size, const char *format, va_list ap);
+  int (*vsnprintf)(char *str, size_t size, const char *format, ...);
   pid_t (*waitpid)(pid_t pid, int *stat_loc, int options);
   ssize_t (*write)(int, void *, size_t);
   double (*atof)();