diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md
index d3a6f7bd3f4..5b608371d46 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+* Fixed an issue for spans when `server.port` attribute was not set with
+  `server.address` when it has default values (`80` for `HTTP` and
+  `443` for `HTTPS` protocol).
+  ([#5419](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5419))
+
 ## 1.7.1
 
 Released 2024-Feb-09
diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs
index 97807d41512..a216a31d298 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInListener.cs
@@ -185,9 +185,9 @@ public void OnStartActivity(Activity activity, object payload)
             {
                 activity.SetTag(SemanticConventions.AttributeServerAddress, request.Host.Host);
 
-                if (request.Host.Port is not null && request.Host.Port != 80 && request.Host.Port != 443)
+                if (request.Host.Port.HasValue)
                 {
-                    activity.SetTag(SemanticConventions.AttributeServerPort, request.Host.Port);
+                    activity.SetTag(SemanticConventions.AttributeServerPort, request.Host.Port.Value);
                 }
             }
 
diff --git a/src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md b/src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md
index b634f2b943a..9b7fa69f2f8 100644
--- a/src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md
+++ b/src/OpenTelemetry.Instrumentation.Http/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+* Fixed an issue for spans when `server.port` attribute was not set with
+  `server.address` when it has default values (`80` for `HTTP` and
+  `443` for `HTTPS` protocol).
+  ([#5419](https://github.com/open-telemetry/opentelemetry-dotnet/pull/5419))
+
 ## 1.7.1
 
 Released 2024-Feb-09
diff --git a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs
index e0625b420db..8132c92fa28 100644
--- a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerDiagnosticListener.cs
@@ -147,10 +147,7 @@ public void OnStartActivity(Activity activity, object payload)
             RequestMethodHelper.SetHttpMethodTag(activity, request.Method.Method);
 
             activity.SetTag(SemanticConventions.AttributeServerAddress, request.RequestUri.Host);
-            if (!request.RequestUri.IsDefaultPort)
-            {
-                activity.SetTag(SemanticConventions.AttributeServerPort, request.RequestUri.Port);
-            }
+            activity.SetTag(SemanticConventions.AttributeServerPort, request.RequestUri.Port);
 
             activity.SetTag(SemanticConventions.AttributeUrlFull, HttpTagHelper.GetUriTagValueFromRequestUri(request.RequestUri));
 
diff --git a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs
index c27bef64132..620cfcc75d0 100644
--- a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpWebRequestActivitySource.netfx.cs
@@ -103,10 +103,7 @@ private static void AddRequestTagsAndInstrumentRequest(HttpWebRequest request, A
             RequestMethodHelper.SetHttpMethodTag(activity, request.Method);
 
             activity.SetTag(SemanticConventions.AttributeServerAddress, request.RequestUri.Host);
-            if (!request.RequestUri.IsDefaultPort)
-            {
-                activity.SetTag(SemanticConventions.AttributeServerPort, request.RequestUri.Port);
-            }
+            activity.SetTag(SemanticConventions.AttributeServerPort, request.RequestUri.Port);
 
             activity.SetTag(SemanticConventions.AttributeUrlFull, HttpTagHelper.GetUriTagValueFromRequestUri(request.RequestUri));