diff --git a/src/polymap.c b/src/polymap.c
index 0b436cc..1aee268 100644
--- a/src/polymap.c
+++ b/src/polymap.c
@@ -165,7 +165,7 @@ f     - AST_POLYTRAN: Fit a PolyMap inverse or forward transformation
 #include "cmpmap.h"              /* Compound mappings */
 #include "polymap.h"             /* Interface definition for this class */
 #include "unitmap.h"             /* Unit mappings */
-#include "cminpack/cminpack.h"   /* Levenberg - Marquardt minimization */
+#include "cminpack-1/cminpack.h"   /* Levenberg - Marquardt minimization */
 #include "pal.h"                 /* SLALIB function definitions */
 
 /* Error code definitions. */