diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a450bc5..75da0a53 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -334,6 +334,7 @@ if(CRYPTO_BACKEND STREQUAL "OpenSSL" OR NOT CRYPTO_BACKEND)
 
     if(ZLIB_FOUND)
       list(APPEND LIBRARIES ${ZLIB_LIBRARIES})
+      list(APPEND LIBSSH2_PC_LIBS_PRIVATE -lz)
     endif()
   endif()
 endif()
@@ -360,6 +361,7 @@ if(CRYPTO_BACKEND STREQUAL "wolfSSL" OR NOT CRYPTO_BACKEND)
     if(ZLIB_FOUND)
       list(APPEND CRYPTO_BACKEND_INCLUDE_DIR ${ZLIB_INCLUDE_DIR})  # Public wolfSSL headers require zlib headers
       list(APPEND LIBRARIES ${ZLIB_LIBRARIES})
+      list(APPEND LIBSSH2_PC_LIBS_PRIVATE -lz)
     endif()
   endif()
 endif()
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 16431faf..17674ccb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -58,6 +58,7 @@ if(ENABLE_ZLIB_COMPRESSION)
 
   list(APPEND libssh2_INCLUDE_DIRS ${ZLIB_INCLUDE_DIRS})
   list(APPEND LIBRARIES ${ZLIB_LIBRARIES})
+  list(APPEND LIBSSH2_PC_LIBS_PRIVATE -lz)
   list(APPEND LIBSSH2_PC_REQUIRES_PRIVATE zlib)
   if(ZLIB_FOUND)
     list(APPEND libssh2_DEFINITIONS LIBSSH2_HAVE_ZLIB)
@@ -184,6 +185,7 @@ if(LIBSSH2_PC_REQUIRES_PRIVATE)
   string(REPLACE ";" "," LIBSSH2_PC_REQUIRES_PRIVATE "${LIBSSH2_PC_REQUIRES_PRIVATE}")
 endif()
 if(LIBSSH2_PC_LIBS_PRIVATE)
+  list(REMOVE_DUPLICATES LIBSSH2_PC_LIBS_PRIVATE)
   string(REPLACE ";" " " LIBSSH2_PC_LIBS_PRIVATE "${LIBSSH2_PC_LIBS_PRIVATE}")
 endif()
 # merge the pkg-config private fields into public ones when static-only