diff --git a/src/libwebp.pc.in b/src/libwebp.pc.in
index e9e785d0..733bb6db 100644
--- a/src/libwebp.pc.in
+++ b/src/libwebp.pc.in
@@ -8,4 +8,4 @@ Description: Library for the WebP graphics format
 Version: @PACKAGE_VERSION@
 Cflags: -I${includedir}
 Libs: -L${libdir} -lwebp
-Libs.private: -lm
+Libs.private: -lm @PTHREAD_CFLAGS@ @PTHREAD_LIBS@
diff --git a/src/libwebpdecoder.pc.in b/src/libwebpdecoder.pc.in
index 9a9d16e1..3ef647a9 100644
--- a/src/libwebpdecoder.pc.in
+++ b/src/libwebpdecoder.pc.in
@@ -8,4 +8,4 @@ Description: Library for the WebP graphics format (decode only)
 Version: @PACKAGE_VERSION@
 Cflags: -I${includedir}
 Libs: -L${libdir} -lwebpdecoder
-Libs.private: -lm
+Libs.private: -lm @PTHREAD_CFLAGS@ @PTHREAD_LIBS@