diff --git a/config.m4 b/config.m4
index 12b10578e898c887a0475bfb8446f4855d6f531e..85549e5f4270cd07b503ab6b9d0dfeb77c2ed1e3 100644
--- a/config.m4
+++ b/config.m4
@@ -5,9 +5,9 @@ if test "$PHP_GRPC" != "no"; then
   dnl Write more examples of tests here...
 
   dnl # --with-grpc -> add include path
-  PHP_ADD_INCLUDE(../../grpc/include)
-  PHP_ADD_INCLUDE(../../grpc/src/php/ext/grpc)
-  PHP_ADD_INCLUDE(../../grpc/third_party/boringssl/include)
+  PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/include)
+  PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/src/php/ext/grpc)
+  PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/third_party/boringssl/include)
 
   LIBS="-lpthread $LIBS"
 
diff --git a/templates/config.m4.template b/templates/config.m4.template
index 5847d456f51c89c941065e04344f86ce0a2f4469..f5f1d23088dadeaedff737fc148349a366a6d484 100644
--- a/templates/config.m4.template
+++ b/templates/config.m4.template
@@ -7,9 +7,9 @@
     dnl Write more examples of tests here...
 
     dnl # --with-grpc -> add include path
-    PHP_ADD_INCLUDE(../../grpc/include)
-    PHP_ADD_INCLUDE(../../grpc/src/php/ext/grpc)
-    PHP_ADD_INCLUDE(../../grpc/third_party/boringssl/include)
+    PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/include)
+    PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/src/php/ext/grpc)
+    PHP_ADD_INCLUDE(PHP_EXT_SRCDIR()/third_party/boringssl/include)
 
     LIBS="-lpthread $LIBS"