diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3ed6665435..8f11cd62c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ librdkafka v2.1.1 is a maintenance release:
    calling `rd_kafka_message_leader_epoch()` on the polled `rkmessage` (#4245).
  * Fix a segmentation fault when fetching from follower and the partition lease
    expires while waiting for the result of a list offsets operation (#4254).
+ * Fix CMake pkg-config cURL require and use
+   pkg-config `Requires.private` field (@FantasqueX, @stertingen, #4180).
 
 ## Fixes
 
diff --git a/packaging/cmake/rdkafka.pc.in b/packaging/cmake/rdkafka.pc.in
index 0eb17e8560..9632cf5134 100644
--- a/packaging/cmake/rdkafka.pc.in
+++ b/packaging/cmake/rdkafka.pc.in
@@ -6,7 +6,7 @@ libdir=${prefix}/lib
 Name: @PKG_CONFIG_NAME@
 Description: @PKG_CONFIG_DESCRIPTION@
 Version: @PKG_CONFIG_VERSION@
-Requires: @PKG_CONFIG_REQUIRES@
+Requires.private: @PKG_CONFIG_REQUIRES_PRIVATE@
 Cflags: @PKG_CONFIG_CFLAGS@
 Libs: @PKG_CONFIG_LIBS@
 Libs.private: @PKG_CONFIG_LIBS_PRIVATE@
diff --git a/src-cpp/CMakeLists.txt b/src-cpp/CMakeLists.txt
index b0a6d51e47..2b496d9f9e 100644
--- a/src-cpp/CMakeLists.txt
+++ b/src-cpp/CMakeLists.txt
@@ -41,7 +41,7 @@ set(PKG_CONFIG_VERSION "${PROJECT_VERSION}")
 if(NOT RDKAFKA_BUILD_STATIC)
   set(PKG_CONFIG_NAME "librdkafka++")
   set(PKG_CONFIG_DESCRIPTION "The Apache Kafka C/C++ library")
-  set(PKG_CONFIG_REQUIRES "rdkafka")
+  set(PKG_CONFIG_REQUIRES_PRIVATE "rdkafka")
   set(PKG_CONFIG_CFLAGS "-I\${includedir}")
   set(PKG_CONFIG_LIBS "-L\${libdir} -lrdkafka++")
   set(PKG_CONFIG_LIBS_PRIVATE "-lrdkafka")
@@ -57,7 +57,7 @@ if(NOT RDKAFKA_BUILD_STATIC)
 else()
   set(PKG_CONFIG_NAME "librdkafka++-static")
   set(PKG_CONFIG_DESCRIPTION "The Apache Kafka C/C++ library (static)")
-  set(PKG_CONFIG_REQUIRES "")
+  set(PKG_CONFIG_REQUIRES_PRIVATE "")
   set(PKG_CONFIG_CFLAGS "-I\${includedir} -DLIBRDKAFKA_STATICLIB")
   set(PKG_CONFIG_LIBS "-L\${libdir} \${libdir}/librdkafka++.a")
   if(WIN32)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 37b43c4996..33481ba1ac 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -199,7 +199,7 @@ target_include_directories(rdkafka PUBLIC "$<BUILD_INTERFACE:${dummy}>")
 
 if(WITH_CURL)
   find_package(CURL REQUIRED)
-  target_include_directories(rdkafka PUBLIC ${CURL_INCLUDE_DIRS})
+  target_include_directories(rdkafka PRIVATE ${CURL_INCLUDE_DIRS})
   target_link_libraries(rdkafka PUBLIC ${CURL_LIBRARIES})
 endif()
 
@@ -272,7 +272,7 @@ endif()
 
 # Generate pkg-config file
 set(PKG_CONFIG_VERSION "${PROJECT_VERSION}")
-set(PKG_CONFIG_REQUIRES "")
+set(PKG_CONFIG_REQUIRES_PRIVATE "")
 if (WIN32)
   set(PKG_CONFIG_LIBS_PRIVATE "-lws2_32 -lsecur32 -lcrypt32")
 else()
@@ -296,27 +296,27 @@ if(NOT RDKAFKA_BUILD_STATIC)
   set(PKG_CONFIG_DESCRIPTION "The Apache Kafka C/C++ library")
 
   if(WITH_CURL)
-    string(APPEND PKG_CONFIG_REQUIRES "curl ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "libcurl ")
   endif()
 
   if(WITH_ZLIB)
-    string(APPEND PKG_CONFIG_REQUIRES "zlib ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "zlib ")
   endif()
 
   if(WITH_SSL)
-    string(APPEND PKG_CONFIG_REQUIRES "libssl ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "libcrypto libssl ")
   endif()
 
   if(WITH_SASL_CYRUS)
-    string(APPEND PKG_CONFIG_REQUIRES "libsasl2 ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "libsasl2 ")
   endif()
 
   if(WITH_ZSTD)
-    string(APPEND PKG_CONFIG_REQUIRES "libzstd ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "libzstd ")
   endif()
 
   if(WITH_LZ4_EXT)
-    string(APPEND PKG_CONFIG_REQUIRES "liblz4 ")
+    string(APPEND PKG_CONFIG_REQUIRES_PRIVATE "liblz4 ")
   endif()
 
   set(PKG_CONFIG_CFLAGS "-I\${includedir}")