diff --git a/eclass/apache-2.eclass b/eclass/apache-2.eclass
index 336ae77d0150c..4728f78553fb9 100644
--- a/eclass/apache-2.eclass
+++ b/eclass/apache-2.eclass
@@ -144,7 +144,7 @@ RDEPEND="
 	dev-libs/libpcre2
 	virtual/libcrypt:=
 	apache2_modules_brotli? ( >=app-arch/brotli-0.6.0:= )
-	apache2_modules_deflate? ( virtual/zlib )
+	apache2_modules_deflate? ( virtual/zlib:= )
 	apache2_modules_http2? (
 		>=net-libs/nghttp2-${NGHTTP2_VERSION}:=
 		kernel_linux? ( sys-apps/util-linux )
diff --git a/eclass/emboss-r3.eclass b/eclass/emboss-r3.eclass
index 797d5f937b190..bc2c6c043c6ed 100644
--- a/eclass/emboss-r3.eclass
+++ b/eclass/emboss-r3.eclass
@@ -53,7 +53,7 @@ RDEPEND="
 	dev-libs/expat
 	dev-libs/libpcre:3
 	sci-libs/plplot:=
-	virtual/zlib
+	virtual/zlib:=
 	mysql? ( dev-db/mysql-connector-c:0= )
 	pdf? ( media-libs/libharu:= )
 	png? ( media-libs/gd:2=[png] )
diff --git a/eclass/toolchain.eclass b/eclass/toolchain.eclass
index 63f4224046d10..52b38412e2b00 100644
--- a/eclass/toolchain.eclass
+++ b/eclass/toolchain.eclass
@@ -354,7 +354,7 @@ fi
 #---->> DEPEND <<----
 
 RDEPEND="
-	virtual/zlib
+	virtual/zlib:=
 	virtual/libiconv
 	nls? ( virtual/libintl )
 "