diff --git a/configure.ac b/configure.ac
index 0f26c493b7..f354cd8bd1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1559,7 +1559,7 @@ if test X"$OPT_ZSTD" != Xno; then
          AC_MSG_NOTICE([Added $DIR_ZSTD to CURL_LIBRARY_PATH])
        fi
     fi
-    LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE zstd"
+    LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libzstd"
   else
     dnl no zstd, revert back to clean variables
     LDFLAGS=$CLEANLDFLAGS
@@ -2912,7 +2912,7 @@ if test X"$want_tcp2" != Xno; then
           CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_TCP2"
           export CURL_LIBRARY_PATH
           AC_MSG_NOTICE([Added $DIR_TCP2 to CURL_LIBRARY_PATH])
-          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE ngtcp2"
+          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libngtcp2"
        )
       ],
         dnl not found, revert back to clean variables
@@ -2969,7 +2969,7 @@ if test "x$NGTCP2_ENABLED" = "x1" -a "x$OPENSSL_ENABLED" = "x1" -a "x$OPENSSL_IS
           CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_NGTCP2_CRYPTO_QUICTLS"
           export CURL_LIBRARY_PATH
           AC_MSG_NOTICE([Added $DIR_NGTCP2_CRYPTO_QUICTLS to CURL_LIBRARY_PATH])
-          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE ngtcp2_crypto_quictls"
+          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libngtcp2_crypto_quictls"
        )
       ],
         dnl not found, revert back to clean variables
@@ -3025,7 +3025,7 @@ if test "x$NGTCP2_ENABLED" = "x1" -a "x$OPENSSL_ENABLED" = "x1" -a "x$OPENSSL_IS
           CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_NGTCP2_CRYPTO_BORINGSSL"
           export CURL_LIBRARY_PATH
           AC_MSG_NOTICE([Added $DIR_NGTCP2_CRYPTO_BORINGSSL to CURL_LIBRARY_PATH])
-          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE ngtcp2_crypto_boringssl"
+          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libngtcp2_crypto_boringssl"
        )
       ],
         dnl not found, revert back to clean variables
@@ -3081,7 +3081,7 @@ if test "x$NGTCP2_ENABLED" = "x1" -a "x$GNUTLS_ENABLED" = "x1"; then
           CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_NGTCP2_CRYPTO_GNUTLS"
           export CURL_LIBRARY_PATH
           AC_MSG_NOTICE([Added $DIR_NGTCP2_CRYPTO_GNUTLS to CURL_LIBRARY_PATH])
-          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE ngtcp2_crypto_gnutls"
+          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libngtcp2_crypto_gnutls"
        )
       ],
         dnl not found, revert back to clean variables
@@ -3137,7 +3137,7 @@ if test "x$NGTCP2_ENABLED" = "x1" -a "x$WOLFSSL_ENABLED" = "x1"; then
           CURL_LIBRARY_PATH="$CURL_LIBRARY_PATH:$DIR_NGTCP2_CRYPTO_WOLFSSL"
           export CURL_LIBRARY_PATH
           AC_MSG_NOTICE([Added $DIR_NGTCP2_CRYPTO_WOLFSSL to CURL_LIBRARY_PATH])
-          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE ngtcp2_crypto_wolfssl"
+          LIBCURL_PC_REQUIRES_PRIVATE="$LIBCURL_PC_REQUIRES_PRIVATE libngtcp2_crypto_wolfssl"
        )
       ],
         dnl not found, revert back to clean variables