diff --git a/configure.in b/configure.in
index 22f26c5..5f9591e 100644
--- a/configure.in
+++ b/configure.in
@@ -18,5 +18,11 @@ dnl ---------------------------------------------
 AC_CHECK_HEADER(X11/Xaw/Form.h,,
        [AC_MSG_ERROR([you need to install libxaw header files (-dev package)])])
 
+dnl ---------------------------------------------
+dnl Check for NSPR include directory
+dnl ---------------------------------------------
+AC_CHECK_PROG(PKGCONFIGFOUND, pkg-config,[yes])
+PKG_CHECK_MODULES(NSPR, nspr, have_nspr=yes,
+    [ AC_MSG_ERROR([nspr library not found on your system]) ])
 
 AC_OUTPUT(Makefile src/Makefile)
diff --git a/src/Makefile.am b/src/Makefile.am
index a0227fa..8a6d324 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,7 +1,7 @@
 
 EXTRA_DIST = npapi.h npunix.c npupp.h plugin.c plugin.h
 
-AM_CFLAGS = @CFLAGS@ $(X_CFLAGS) 
+AM_CFLAGS = @CFLAGS@ $(X_CFLAGS) $(NSPR_CFLAGS)
 
 
 lib_LTLIBRARIES = kaffeineplugin.la
diff --git a/src/jni_md.h b/src/jni_md.h
index d6d2d71..5723bc4 100644
--- a/src/jni_md.h
+++ b/src/jni_md.h
@@ -40,7 +40,7 @@
 #ifndef JNI_MD_H
 #define JNI_MD_H
 
-#include <nspr/prtypes.h> /* needed for _declspec */
+#include <prtypes.h> /* needed for _declspec */
 
 /*******************************************************************************
  * WHAT'S UP WITH THIS FILE?
diff --git a/src/jri_md.h b/src/jri_md.h
index 800b70f..301053c 100644
--- a/src/jri_md.h
+++ b/src/jri_md.h
@@ -43,7 +43,7 @@
 #define JRI_MD_H
 
 #include <assert.h>
-#include <nspr/prtypes.h> /* Needed for HAS_LONG_LONG ifdefs */
+#include <prtypes.h> /* Needed for HAS_LONG_LONG ifdefs */
 
 #ifdef __cplusplus
 extern "C" {