diff --git a/mx.fastr/compilers/fastr-c++ b/mx.fastr/compilers/fastr-c++
index 4a2d1badc826d3123df559a7453bc2ee1971af7f..940ad0e0fecc1dc732cdb565d4a3d7301a322560 100755
--- a/mx.fastr/compilers/fastr-c++
+++ b/mx.fastr/compilers/fastr-c++
@@ -40,7 +40,7 @@ while [ $DIR != "/" ] ; do
 done
 
 if [ $with_sulong = 1 ] && [ "$FASTR_SULONG_IGNORE" = "" ] ; then
-    mx --dynamicimport sulong fastr-c++ $@
+    MX_PRIMARY_SUITE_PATH=$DIR/fastr mx --dynamicimport sulong fastr-c++ $@
 else
     g++ $@
 fi
diff --git a/mx.fastr/compilers/fastr-cc b/mx.fastr/compilers/fastr-cc
index bd1c5737234b788d92b254b77a96ab3ddb5ae7e0..30f313e3a287814402448df82b89f8b5978464f4 100755
--- a/mx.fastr/compilers/fastr-cc
+++ b/mx.fastr/compilers/fastr-cc
@@ -40,7 +40,7 @@ while [ $DIR != "/" ] ; do
 done
 
 if [ $with_sulong = 1 ] && [ "$FASTR_SULONG_IGNORE" = "" ] ; then
-	mx --dynamicimport sulong fastr-cc $@
+	MX_PRIMARY_SUITE_PATH=$DIR/fastr mx --dynamicimport sulong fastr-cc $@
 else
     gcc $@
 fi
diff --git a/mx.fastr/compilers/fastr-cpp b/mx.fastr/compilers/fastr-cpp
index 10fc355b3f66f713ef7b72e0b583c86d95af00e6..26444e34c001fa91a9208e99298ebc830aaff4c0 100755
--- a/mx.fastr/compilers/fastr-cpp
+++ b/mx.fastr/compilers/fastr-cpp
@@ -40,7 +40,7 @@ while [ $DIR != "/" ] ; do
 done
 
 if [ $with_sulong = 1 ] && [ "$FASTR_SULONG_IGNORE" = "" ] ; then
-	mx --dynamicimport sulong fastr-cpp $@
+	MX_PRIMARY_SUITE_PATH=$DIR/fastr mx --dynamicimport sulong fastr-cpp $@
 else
     cpp $@
 fi
diff --git a/mx.fastr/compilers/fastr-fc b/mx.fastr/compilers/fastr-fc
index e5d38d6206de50d51f8c4605e7e4bba08dee1405..741eacb49c1f0f2a130e39c9702646898f842fdf 100755
--- a/mx.fastr/compilers/fastr-fc
+++ b/mx.fastr/compilers/fastr-fc
@@ -40,7 +40,7 @@ while [ $DIR != "/" ] ; do
 done
 
 if [ $with_sulong = 1 ] && [ "$FASTR_SULONG_IGNORE" = "" ] ; then
-    mx --dynamicimport sulong fastr-fc $@
+    MX_PRIMARY_SUITE_PATH=$DIR/fastr mx --dynamicimport sulong fastr-fc $@
 else
     gfortran $@
 fi