diff --git a/bin/ocamlcflags b/bin/ocamlcflags
new file mode 100755
index 00000000..224725d3
--- /dev/null
+++ b/bin/ocamlcflags
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+OCAML_VERSION_MAJOR=`ocamlc -version | cut -f1 -d.`
+#OCAML_VERSION_MINOR = `ocamlopt -version | cut -f2 -d.`
+#OCAML_VERSION_POINT = `ocamlopt -version | cut -f3 -d.`
+
+case "$OCAML_VERSION_MAJOR" in
+    "3") ;;
+    "4")
+       echo "-absname -bin-annot";;
+    "5")
+       echo "-absname -bin-annot";;
+    "*") ;;
+esac
diff --git a/mkconfig b/mkconfig
index 09b2a243..41bd7a9c 100644
--- a/mkconfig
+++ b/mkconfig
@@ -4,12 +4,12 @@ OPT=.opt
 
 # Limit to just stdcompat! This is Xix!
 EXTERNAL_LIB=`ocamlfind query stdcompat`
+EXTRA_FLAGS=`ocamlcflags`
 
 # -g so we can get good backtrace
-#TODO: -bin-annot -absname
 #WARNING_FLAGS?=-w +A-4-29-6-45-41-44-48 -warn-error +a 
 #OCAMLCFLAGS=-thread $(WARNING_FLAGS) $(OCAMLCFLAGS_EXTRA)
-COMPFLAGS=-I $EXTERNAL_LIB -g
+COMPFLAGS=-I $EXTERNAL_LIB -g $EXTRA_FLAGS
 
 # We need -g for good backtrace.
 # We need -custom because of dllstdcompat__stubs, otherwise