diff --git a/Makefile.FreeBSD b/Makefile.FreeBSD
index 018846be1e7..7fa0f3d49cc 100644
--- a/Makefile.FreeBSD
+++ b/Makefile.FreeBSD
@@ -22,6 +22,9 @@ PLATFORMLINKOPTS := -Wl,--export-dynamic
 # stripped from the resultant binary.
 PLATFORMSTRIPOPTS := -Wl,-x
 
+# PLATFORMLIBDL - FreeBSD does not have libdl; dlsym() is in libc.
+PLATFORMLIBDL := 
+
 # Path to location for LLVM front-end for this architecture.  This setting may
 # be overriden by the Makefile.config option, and should not override it if set.
 # (Using Linux GCC front-end for now.)
diff --git a/Makefile.Linux b/Makefile.Linux
index 553004d7a6d..18b50c268dc 100644
--- a/Makefile.Linux
+++ b/Makefile.Linux
@@ -22,6 +22,9 @@ PLATFORMLINKOPTS := -Wl,--export-dynamic
 # stripped from the resultant binary.
 PLATFORMSTRIPOPTS := -Wl,-x
 
+# PLATFORMLIBDL - Library that supports dlsym() et al. 
+PLATFORMLIBDL := -ldl
+
 # Path to location for LLVM front-end for this architecture.  This setting may
 # be overriden by the Makefile.config option, and should not override it if set.
 #
diff --git a/Makefile.SunOS b/Makefile.SunOS
index c6508bf1ed5..bc6b49fe775 100644
--- a/Makefile.SunOS
+++ b/Makefile.SunOS
@@ -24,6 +24,9 @@ PLATFORMLINKOPTS := -lmalloc
 #
 PLATFORMSTRIPOPTS :=
 
+# PLATFORMLIBDL - Library that supports dlsym() et al. 
+PLATFORMLIBDL := -ldl
+
 # Path to location for LLVM front-end for this architecture.  This setting may
 # be overriden by the Makefile.config option, and should not override it if set.
 #