diff --git a/ChangeLog b/ChangeLog
index 342017718f..7cbbb3f74d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -36,6 +36,7 @@ Security
 Bugfix
    * Fix compile error in net.c with musl libc. Found and patch provided by
      zhasha (#278).
+   * Fix macroization of 'inline' keyword when building as C++. (#279)
 
 Changes
    * Added checking of hostname length in mbedtls_ssl_set_hostname() to ensure
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 87d9c79f56..70000f5e61 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -46,7 +46,8 @@
 #define MBEDTLS_CIPHER_MODE_STREAM
 #endif
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif
 
diff --git a/include/mbedtls/md.h b/include/mbedtls/md.h
index 1834b59927..77c2c6f680 100644
--- a/include/mbedtls/md.h
+++ b/include/mbedtls/md.h
@@ -27,10 +27,6 @@
 
 #include <stddef.h>
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
-#define inline __inline
-#endif
-
 #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE                -0x5080  /**< The selected feature is not available. */
 #define MBEDTLS_ERR_MD_BAD_INPUT_DATA                     -0x5100  /**< Bad input parameters to function. */
 #define MBEDTLS_ERR_MD_ALLOC_FAILED                       -0x5180  /**< Failed to allocate memory. */
diff --git a/include/mbedtls/pkcs11.h b/include/mbedtls/pkcs11.h
index 7632929cb6..2e88928137 100644
--- a/include/mbedtls/pkcs11.h
+++ b/include/mbedtls/pkcs11.h
@@ -37,7 +37,8 @@
 
 #include <pkcs11-helper-1.0/pkcs11h-certificate.h>
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif
 
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 73279a5ae2..78c748cfa0 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -41,7 +41,8 @@
 #include "sha512.h"
 #endif
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif
 
diff --git a/library/debug.c b/library/debug.c
index 070f63a724..4752ab1a39 100644
--- a/library/debug.c
+++ b/library/debug.c
@@ -42,7 +42,8 @@
 #define mbedtls_snprintf    snprintf
 #endif
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif
 
diff --git a/library/ecp.c b/library/ecp.c
index 858540be20..64a47ab521 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -62,7 +62,8 @@
 #define mbedtls_free       free
 #endif
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif
 
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 68323c5823..9a6e8eb187 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -31,7 +31,8 @@
 
 #include <string.h>
 
-#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && !defined(inline)
+#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
+    !defined(inline) && !defined(__cplusplus)
 #define inline __inline
 #endif