diff --git a/Algebraic_kernel_for_circles/test/Algebraic_kernel_for_circles/GNUmakefile b/Algebraic_kernel_for_circles/test/Algebraic_kernel_for_circles/GNUmakefile
index f1e81a3c3fa..322caa96bd9 100644
--- a/Algebraic_kernel_for_circles/test/Algebraic_kernel_for_circles/GNUmakefile
+++ b/Algebraic_kernel_for_circles/test/Algebraic_kernel_for_circles/GNUmakefile
@@ -51,6 +51,6 @@ clean: \
 #                    suffix rules
 #---------------------------------------------------------------------#
 
-.C$(OBJ_EXT):
+.cpp$(OBJ_EXT):
 	$(CGAL_CXX) $(CXXFLAGS) $(OBJ_OPT) $<