diff --git a/src/poetry/core/packages/utils/utils.py b/src/poetry/core/packages/utils/utils.py
index 74a119e84..c5d059946 100644
--- a/src/poetry/core/packages/utils/utils.py
+++ b/src/poetry/core/packages/utils/utils.py
@@ -320,7 +320,7 @@ def normalize_python_version_markers(  # NOSONAR
                 version = "~" + version
                 op = ""
 
-            elif op == "!=" and "*" not in version:
+            elif op == "!=" and "*" not in version and version.count(".") < 2:
                 version += ".*"
 
             elif op in ("<=", ">"):
diff --git a/tests/packages/utils/test_utils.py b/tests/packages/utils/test_utils.py
index 8be34affc..0d4e3e89e 100644
--- a/tests/packages/utils/test_utils.py
+++ b/tests/packages/utils/test_utils.py
@@ -129,6 +129,11 @@ def test_convert_markers(
         ('python_version >= "3.9" or sys_platform == "linux"', "*"),
         # relevant python_version
         ('python_version >= "3.9" and sys_platform == "linux"', ">=3.9"),
+        # exclude specific version
+        (
+            'python_version >= "3.5" and python_full_version !="3.7.6"',
+            ">=3.5,<3.7.6 || >3.7.6",
+        ),
     ],
 )
 def test_get_python_constraint_from_marker(marker: str, constraint: str) -> None: