diff --git a/core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java b/core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java
index e768ba4a9fe..14082a2a2ae 100644
--- a/core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java
+++ b/core/src/main/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtil.java
@@ -368,7 +368,7 @@ private static String simpleConcat(String prefix, String path) {
      * Decodes a percent-encoded path string.
      */
     public static String decodePath(String path) {
-        if (path.indexOf('%') < 0) {
+        if (path.indexOf('%') < 0 && path.indexOf('+') < 0) {
             // No need to decode because it's not percent-encoded
             return path;
         }
@@ -407,6 +407,11 @@ private static String slowDecodePath(String path, boolean decodeSlash) {
             int dstLen = 0;
             for (int i = 0; i < len; i++) {
                 final char ch = path.charAt(i);
+                if (ch == '+') {
+                    buf[dstLen++] = (byte) ' ';
+                    continue;
+                }
+
                 if (ch != '%') {
                     buf[dstLen++] = (byte) ((ch & 0xFF80) == 0 ? ch : 0xFF);
                     continue;
diff --git a/core/src/test/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtilTest.java b/core/src/test/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtilTest.java
index d478c8256ae..fbcfdca9b99 100644
--- a/core/src/test/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtilTest.java
+++ b/core/src/test/java/com/linecorp/armeria/internal/common/ArmeriaHttpUtilTest.java
@@ -116,6 +116,12 @@ void testDecodePath(boolean isPathParam) throws Exception {
         } else {
             assertThat(decodeFunc.apply("/%2F")).isEqualTo("/%2F");
         }
+
+        // Tests for '+' decoding into ' '
+        assertThat(decodeFunc.apply("/foo+bar")).isEqualTo("/foo bar"); // '+' should be decoded into space
+        assertThat(decodeFunc.apply("/foo+%20bar")).isEqualTo("/foo  bar"); // '+' and '%20' both decoded to space
+        assertThat(decodeFunc.apply("/foo+bar+baz")).isEqualTo("/foo bar baz"); // multiple '+' should be decoded to space
+        assertThat(decodeFunc.apply("/foo%20bar+baz")).isEqualTo("/foo bar baz"); // combination of '%20' and '+'
     }
 
     @Test