diff --git a/sci-physics/vgm/vgm-4.4-r1.ebuild b/sci-physics/vgm/vgm-4.4-r1.ebuild
index 89f9a9ec13842..ccda066630dd9 100644
--- a/sci-physics/vgm/vgm-4.4-r1.ebuild
+++ b/sci-physics/vgm/vgm-4.4-r1.ebuild
@@ -47,7 +47,7 @@ PATCHES=(
 
 src_configure() {
 	local mycmakeargs=(
-		-DCLHEP_DIR="${EROOT}usr"
+		-DCLHEP_DIR="${EPREFIX}/usr"
 		-DWITH_EXAMPLES="$(usex examples)"
 		-DINSTALL_EXAMPLES="$(usex examples)"
 		-DWITH_GEANT4="$(usex geant4)"
diff --git a/sci-physics/vgm/vgm-4.5.ebuild b/sci-physics/vgm/vgm-4.5.ebuild
index 7053d1d2a92da..16c08cfb93205 100644
--- a/sci-physics/vgm/vgm-4.5.ebuild
+++ b/sci-physics/vgm/vgm-4.5.ebuild
@@ -47,7 +47,7 @@ PATCHES=(
 
 src_configure() {
 	local mycmakeargs=(
-		-DCLHEP_DIR="${EROOT}usr"
+		-DCLHEP_DIR="${EPREFIX}/usr"
 		-DWITH_EXAMPLES="$(usex examples)"
 		-DINSTALL_EXAMPLES="$(usex examples)"
 		-DWITH_GEANT4="$(usex geant4)"
diff --git a/sci-physics/vgm/vgm-9999.ebuild b/sci-physics/vgm/vgm-9999.ebuild
index 00846ae113bd6..8443bf3f67a9f 100644
--- a/sci-physics/vgm/vgm-9999.ebuild
+++ b/sci-physics/vgm/vgm-9999.ebuild
@@ -44,7 +44,7 @@ DOCS=(
 
 src_configure() {
 	local mycmakeargs=(
-		-DCLHEP_DIR="${EROOT}usr"
+		-DCLHEP_DIR="${EPREFIX}/usr"
 		-DWITH_EXAMPLES="$(usex examples)"
 		-DINSTALL_EXAMPLES="$(usex examples)"
 		-DWITH_GEANT4="$(usex geant4)"