diff --git a/BUILD.bazel b/BUILD.bazel
index a42e5be..de64ee2 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -17,6 +17,13 @@ cc_library(
     name = "ncrypto",
     srcs = glob(["src/*.cpp"]),
     hdrs = glob(["include/*.h", "include/ncrypto/*.h"]),
+    copts = [
+        "-Werror",
+        "-Wextra",
+        "-Wno-unused-parameter",
+        "-Wimplicit-fallthrough",
+        "-Wno-deprecated-declarations",  # OpenSSL 3.0 deprecates many APIs we intentionally use
+    ],
     includes = ["include"],
     local_defines = {
         "NCRYPTO_BSSL_LIBDECREPIT_MISSING": select(
diff --git a/include/ncrypto/aead.h b/include/ncrypto/aead.h
index 20cf4df..69de329 100644
--- a/include/ncrypto/aead.h
+++ b/include/ncrypto/aead.h
@@ -19,7 +19,7 @@ class Aead final {
 
  public:
   Aead() = default;
-  Aead(const AeadInfo* info, const EVP_AEAD* aead) : info_(info), aead_(aead) {}
+  Aead(const AeadInfo* info, const EVP_AEAD* aead) : aead_(aead), info_(info) {}
   Aead(const Aead&) = default;
   Aead& operator=(const Aead&) = default;
   NCRYPTO_DISALLOW_MOVE(Aead)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 78f61de..4df9bab 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,4 +1,26 @@
 add_library(ncrypto ncrypto.cpp engine.cpp aead.cpp)
+
+# Enable strict warning flags for ncrypto sources only
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang|AppleClang")
+    target_compile_options(ncrypto PRIVATE
+        -Werror
+        -Wextra
+        -Wno-unused-parameter
+        -Wimplicit-fallthrough
+        -Wno-deprecated-declarations  # OpenSSL 3.0 deprecates many APIs we intentionally use
+    )
+elseif(MSVC)
+    target_compile_options(ncrypto PRIVATE
+        /WX     # Treat warnings as errors
+        /W3     # Warning level 3 (production quality)
+        /wd4100 # Unreferenced formal parameter (like -Wno-unused-parameter)
+        /wd4267 # Conversion from 'size_t' to smaller type
+        /wd4244 # Conversion, possible loss of data
+        /wd4305 # Truncation from 'int' to 'bool'
+        /wd4127 # Conditional expression is constant
+    )
+endif()
+
 if (NCRYPTO_SHARED_LIBS)
     target_link_libraries(ncrypto PUBLIC OpenSSL::SSL OpenSSL::Crypto)
 else()