diff --git a/pkgs/development/interpreters/guile/2.0.nix b/pkgs/development/interpreters/guile/2.0.nix
index 8214ca2adcda1..38efe0d919601 100644
--- a/pkgs/development/interpreters/guile/2.0.nix
+++ b/pkgs/development/interpreters/guile/2.0.nix
@@ -121,7 +121,7 @@ builder rec {
   + ''
     sed -i "$out/lib/pkgconfig/guile"-*.pc    \
         -e "s|-lunistring|-L${libunistring}/lib -lunistring|g ;
-            s|^Cflags:\(.*\)$|Cflags: -I${libunistring}/include \1|g ;
+            s|^Cflags:\(.*\)$|Cflags: -I${libunistring.dev}/include \1|g ;
             s|-lltdl|-L${libtool.lib}/lib -lltdl|g ;
             s|includedir=$out|includedir=$dev|g
             "
diff --git a/pkgs/development/interpreters/guile/2.2.nix b/pkgs/development/interpreters/guile/2.2.nix
index 19ef0e6084859..f6df310263427 100644
--- a/pkgs/development/interpreters/guile/2.2.nix
+++ b/pkgs/development/interpreters/guile/2.2.nix
@@ -112,7 +112,7 @@ builder rec {
   + ''
     sed -i "$out/lib/pkgconfig/guile"-*.pc    \
         -e "s|-lunistring|-L${libunistring}/lib -lunistring|g ;
-            s|^Cflags:\(.*\)$|Cflags: -I${libunistring}/include \1|g ;
+            s|^Cflags:\(.*\)$|Cflags: -I${libunistring.dev}/include \1|g ;
             s|-lltdl|-L${libtool.lib}/lib -lltdl|g ;
             s|includedir=$out|includedir=$dev|g
             "
diff --git a/pkgs/development/interpreters/guile/3.0.nix b/pkgs/development/interpreters/guile/3.0.nix
index 5241c03a954e1..7c352ae9bb539 100644
--- a/pkgs/development/interpreters/guile/3.0.nix
+++ b/pkgs/development/interpreters/guile/3.0.nix
@@ -110,7 +110,7 @@ builder rec {
   + ''
     sed -i "$out/lib/pkgconfig/guile"-*.pc    \
         -e "s|-lunistring|-L${libunistring}/lib -lunistring|g ;
-            s|^Cflags:\(.*\)$|Cflags: -I${libunistring}/include \1|g ;
+            s|^Cflags:\(.*\)$|Cflags: -I${libunistring.dev}/include \1|g ;
             s|-lltdl|-L${libtool.lib}/lib -lltdl|g ;
             s|includedir=$out|includedir=$dev|g
             "