diff --git a/model/parsers/qwen3coder.go b/model/parsers/qwen3coder.go
index b0e8ec48cd..a7838fb78b 100644
--- a/model/parsers/qwen3coder.go
+++ b/model/parsers/qwen3coder.go
@@ -393,18 +393,55 @@ func parseValue(raw string, paramType api.PropertyType) any {
 	return raw
 }
 
-var qwenTagRegex = regexp.MustCompile(`<(\w+)=([^>]+)>`)
+var (
+	qwenTagRegex    = regexp.MustCompile(`<(\w+)=([^>]+)>`)
+	qwenXMLTagRegex = regexp.MustCompile(`</?(?:function|parameter)(?:\s+name="[^"]*")?>`)
+)
 
 // transformToXML transforms a raw qwen tool call with xml-like tags into valid
 // xml so that it can be parsed by any xml parser
 func transformToXML(raw string) string {
 	// take the form `<tag=abc>` and transform it to `<tag name="abc">`, taking
 	// care to properly escape the string that becomes the attribute value
-	return qwenTagRegex.ReplaceAllStringFunc(raw, func(match string) string {
+	transformed := qwenTagRegex.ReplaceAllStringFunc(raw, func(match string) string {
 		groups := qwenTagRegex.FindStringSubmatch(match)
 		tag := groups[1]
 		var escapedValue strings.Builder
 		xml.EscapeText(&escapedValue, []byte(groups[2]))
 		return fmt.Sprintf(`<%s name="%s">`, tag, escapedValue.String())
 	})
+
+	// Walk the resulting string, escaping any character data that sits between the
+	// xml tags we just emitted
+	var out strings.Builder
+	lastIdx := 0
+	for _, loc := range qwenXMLTagRegex.FindAllStringIndex(transformed, -1) {
+		if loc[0] > lastIdx {
+			escapeTextNode(&out, transformed[lastIdx:loc[0]])
+		}
+		out.WriteString(transformed[loc[0]:loc[1]])
+		lastIdx = loc[1]
+	}
+	if lastIdx < len(transformed) {
+		escapeTextNode(&out, transformed[lastIdx:])
+	}
+
+	return out.String()
+}
+
+// escapeTextNode escapes XML character data without altering other characters
+// like newlines or tabs (which is why we don't use xml.EscapeText for this)
+func escapeTextNode(sb *strings.Builder, s string) {
+	for _, r := range s {
+		switch r {
+		case '&':
+			sb.WriteString("&amp;")
+		case '<':
+			sb.WriteString("&lt;")
+		case '>':
+			sb.WriteString("&gt;")
+		default:
+			sb.WriteRune(r)
+		}
+	}
 }
diff --git a/model/parsers/qwen3coder_test.go b/model/parsers/qwen3coder_test.go
index 2389c77b58..43823e6fc6 100644
--- a/model/parsers/qwen3coder_test.go
+++ b/model/parsers/qwen3coder_test.go
@@ -312,6 +312,41 @@ true
 				},
 			},
 		},
+		// regression test for <https://github.com/ollama/ollama/issues/12357>
+		{
+			name:  "ampersands in parameter values",
+			tools: []api.Tool{},
+			rawToolCall: `<function=exec>
+<parameter=command>
+ls && echo "done"
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "exec",
+					Arguments: map[string]any{
+						"command": "ls && echo \"done\"",
+					},
+				},
+			},
+		},
+		{
+			name:  "angle brackets in parameter values",
+			tools: []api.Tool{},
+			rawToolCall: `<function=exec>
+<parameter=command>
+ls && echo "a > b and a < b"
+</parameter>
+</function>`,
+			wantToolCall: api.ToolCall{
+				Function: api.ToolCallFunction{
+					Name: "exec",
+					Arguments: map[string]any{
+						"command": "ls && echo \"a > b and a < b\"",
+					},
+				},
+			},
+		},
 	}
 
 	for i, step := range steps {
@@ -798,6 +833,19 @@ celsius
 </parameter>
 </function>`,
 		},
+		{
+			desc: "ampersands in parameter values",
+			raw: `<function=get_current_temperature>
+		<parameter=location>
+		San Francisco & San Jose
+		</parameter>
+		</function>`,
+			want: `<function name="get_current_temperature">
+		<parameter name="location">
+		San Francisco &amp; San Jose
+		</parameter>
+		</function>`,
+		},
 	}
 
 	for _, tc := range cases {