diff --git a/rts/idris_rts.c b/rts/idris_rts.c
index 43c011160..0d396e4f1 100644
--- a/rts/idris_rts.c
+++ b/rts/idris_rts.c
@@ -419,6 +419,13 @@ VAL MKB64(VM* vm, uint64_t bits64) {
     return cl;
 }
 
+void idris_trace(VM* vm, const char* func, int line) {
+    printf("At %s:%d\n", func, line);
+    dumpStack(vm);
+    puts("");
+    fflush(stdout);
+}
+
 void dumpStack(VM* vm) {
     int i = 0;
     VAL* root;
@@ -426,7 +433,8 @@ void dumpStack(VM* vm) {
     for (root = vm->valstack; root < vm->valstack_top; ++root, ++i) {
         printf("%d: ", i);
         dumpVal(*root);
-        if (*root >= (VAL)(vm->heap.heap) && *root < (VAL)(vm->heap.end)) { printf("OK"); }
+        if (*root >= (VAL)(vm->heap.heap) && *root < (VAL)(vm->heap.end)) { printf(" OK"); }
+        if (root == vm->valstack_base) { printf(" <--- base"); }
         printf("\n");
     }
     printf("RET: ");
diff --git a/rts/idris_rts.h b/rts/idris_rts.h
index 4d5730fdf..e5bdd08c0 100644
--- a/rts/idris_rts.h
+++ b/rts/idris_rts.h
@@ -235,7 +235,15 @@ typedef intptr_t i_int;
 
 // Stack management
 
-#define INITFRAME VAL* myoldbase
+#ifdef IDRIS_TRACE
+#define TRACE idris_trace(vm, __FUNCTION__, __LINE__);
+#else
+#define TRACE 
+#endif
+
+#define INITFRAME TRACE\
+                  VAL* myoldbase
+
 #define REBASE vm->valstack_base = oldbase
 #define RESERVE(x) if (vm->valstack_top+(x) > vm->stack_max) { stackOverflow(); } \
                    else { memset(vm->valstack_top, 0, (x)*sizeof(VAL)); }
@@ -348,6 +356,7 @@ VM* idris_getSender(Msg* msg);
 int idris_getChannel(Msg* msg);
 void idris_freeMsg(Msg* msg);
 
+void idris_trace(VM* vm, const char* func, int line);
 void dumpVal(VAL r);
 void dumpStack(VM* vm);