diff --git a/Makefile b/Makefile
index 7f33dff80b70c52689e1182d8ba0db6bb292f53e..7dbe888d8e58991c867ed8799c8d2d769129ab26 100644
--- a/Makefile
+++ b/Makefile
@@ -25,8 +25,8 @@ FONTSIZE := 20
 SRC := $(basename $(shell grep -l '\\begin{document}' *.tex))
 DIA_PIC := $(basename $(shell ls *.dia))
 GNP := $(basename $(shell ls *.gnp))
-PIC_EXT := .dot .gif .jpg .png .ppm .svg .xcf
-PIC := $(foreach I, $(PIC_EXT), $(basename $(shell ls *$I)))
+PIC_EXT := dot gif jpg png ppm svg xcf
+PIC := $(foreach I, $(PIC_EXT), $(basename $(shell ls *.$I)))
 #PIC_EPS := $(addsuffix .eps, $(PIC))
 
 # Output.