diff --git a/src/app/components/results-graph/results-graph.component.ts b/src/app/components/results-graph/results-graph.component.ts
index 5cc0a4590950a287b9b2d5a42131b4523f1322dc..7e775c89a5dd14cd0f761a21cb7ea25b6326f6d5 100644
--- a/src/app/components/results-graph/results-graph.component.ts
+++ b/src/app/components/results-graph/results-graph.component.ts
@@ -204,11 +204,14 @@ export class ResultsGraphComponent extends ResultsComponent implements AfterCont
                 },
                 label: (tooltipItem, data) => {
                     const lines: string[] = [];
+                    const nbLines = that._results.getVariatingParametersSymbols().length;
                     for (const v of that._results.getVariatingParametersSymbols()) {
                         const series = that._results.getValuesSeries(v);
                         const line = v + " = " + series[tooltipItem.index].toFixed(nDigits);
                         if (v === this.chartX) {
-                            lines.unshift("");
+                            if (nbLines > 1) {
+                                lines.unshift("");
+                            }
                             lines.unshift(line);
                         } else {
                             lines.push(line);
@@ -277,11 +280,14 @@ export class ResultsGraphComponent extends ResultsComponent implements AfterCont
                 },
                 label: (tooltipItem, data) => {
                     const lines: string[] = [];
+                    const nbLines = that._results.getVariatingParametersSymbols().length;
                     for (const v of that._results.getVariatingParametersSymbols()) {
                         const series = that._results.getValuesSeries(v);
                         const line = v + " = " + series[tooltipItem.index].toFixed(nDigits);
                         if (v === this.chartX) {
-                            lines.unshift("");
+                            if (nbLines > 1) {
+                                lines.unshift("");
+                            }
                             lines.unshift(line);
                         } else {
                             lines.push(line);