diff --git a/fsl/scripts/imcp.py b/fsl/scripts/imcp.py
index 77482a28cb2ac7ff9710d796bc01faea466733ce..81f53a83d5fdd682c80f41a208641c3273a8985d 100755
--- a/fsl/scripts/imcp.py
+++ b/fsl/scripts/imcp.py
@@ -60,6 +60,7 @@ def main(argv=None):
         return 1
 
     try:
+        srcs = [fslimage.fixExt(s) for s in srcs]
         srcs = fslpath.removeDuplicates(
             srcs,
             allowedExts=fslimage.ALLOWED_EXTENSIONS,
diff --git a/fsl/scripts/immv.py b/fsl/scripts/immv.py
index 94c9674099497f7aaa2bea30945af7df15afa92a..c25a99e04c535f3cd26690f5600213e4d3d23ebe 100755
--- a/fsl/scripts/immv.py
+++ b/fsl/scripts/immv.py
@@ -61,6 +61,7 @@ def main(argv=None):
         return 1
 
     try:
+        srcs = [fslimage.fixExt(s) for s in srcs]
         srcs = fslpath.removeDuplicates(
             srcs,
             allowedExts=fslimage.ALLOWED_EXTENSIONS,