A compound of formula wherein L 1 is -CH 2 -; L 2 is -CH 2 - or -CH 2 -CH 2 -; and L 3 is -CH 2 - or -CH(CH 3)-; or L 1 is -CH 2 -CH 2 -; L 2 is -CH 2 -; and L 3 is -CH 2 -CH 2 -; L 4 is the group L4b wherein the bond marked with the asterisk is attached to the azabicycloalkyl moiety; X 1 is -O- or -NH-; A 2 is selected from wherein the bond marked with the asterisk is attached to X 1; A 1 is a five- to ten-membered monocyclic or fused polycyclic aromatic ring system which may contain from 1 to 4 hetero atoms selected from nitrogen, oxygen and sulfur, wherein the ring system may contain not more than 2 oxygen atoms and not more than 2 sulfur atoms, and wherein the ring system may be substituted once or more than once by R 2, and wherein a substituent on a nitrogen in a heterocyclic ring system may not be halogen; each R 2 independently is C 1-6 alkyl, C 1-6 halogenalkyl, C 1-6 alkoxy, C 1-6 halogenalkoxy, halogen, cyano or a three- to six-membered monocyclic ring system which may be aromatic, saturated or partially saturated and which may contain from 1 to 4 hetero atoms selected from nitrogen, oxygen and sulfur, and wherein each ring system may contain not more than 2 oxygen atoms and not more than 2 sulfur atoms, and wherein each ring system may in turn be substituted once or more than once by C 1-6 alkyl, C 1-6 halogenalkyl, C 1-6 alkoxy, C 1-6 halogenalkoxy, halogen or cyano, and wherein a substituent on a nitrogen in a heterocyclic ring system may not be halogen; or two R 2 at adjacent ring atoms form a C 3-4 alkylene group, wherein 1-2 carbon atoms may be replaced by X 2, and wherein the C 3-4 alkylene group may be substituted once or more than once by R 3; each X 2 independently is -O- or -N(R 4)-; each R 4 independently is hydrogen or C 1-6 alkyl; and each R 3 independently is halogen or C 1-6 alkyl; in free base form or in acid addition salt form, for use in the treatment, prevention or delay of progression of dyskinesia associated with dopamine agonist therapy in Parkinson's Disease. L 1 is -CH 2 -; L 2 is -CH 2 - or -CH 2 -CH 2 -; and L 3 is -CH 2 - or -CH(CH 3)-; or L 1 is -CH 2 -CH 2 -; L 2 is -CH 2 -; and L 3 is -CH 2 -CH 2 -; L 4 is the group L4b wherein the bond marked with the asterisk is attached to the azabicycloalkyl moiety; X 1 is -O- or -NH-; A 2 is selected from wherein the bond marked with the asterisk is attached to X 1; wherein the bond marked with the asterisk is attached to the azabicycloalkyl moiety; X 1 is -O- or -NH-; A 2 is selected from wherein the bond marked with the asterisk is attached to X 1; A 1 is a five- to ten-membered monocyclic or fused polycyclic aromatic ring system which may contain from 1 to 4 hetero atoms selected from nitrogen, oxygen and sulfur, wherein the ring system may contain not more than 2 oxygen atoms and not more than 2 sulfur atoms, and wherein the ring system may be substituted once or more than once by R 2, and wherein a substituent on a nitrogen in a heterocyclic ring system may not be halogen; each R 2 independently is C 1-6 alkyl, C 1-6 halogenalkyl, C 1-6 alkoxy, C 1-6 halogenalkoxy, halogen, cyano or a three- to six-membered monocyclic ring system which may be aromatic, saturated or partially saturated and which may contain from 1 to 4 hetero atoms selected from nitrogen, oxygen and sulfur, and wherein each ring system may contain not more than 2 oxygen atoms and not more than 2 sulfur atoms, and wherein each ring system may in turn be substituted once or more than once by C 1-6 alkyl, C 1-6 halogenalkyl, C 1-6 alkoxy, C 1-6 halogenalkoxy, halogen or cyano, and wherein a substituent on a nitrogen in a heterocyclic ring system may not be halogen; or two R 2 at adjacent ring atoms form a C 3-4 alkylene group, wherein 1-2 carbon atoms may be replaced by X 2, and wherein the C 3-4 alkylene group may be substituted once or more than once by R 3; each X 2 independently is -O- or -N(R 4)-; each R 4 independently is hydrogen or C 1-6 alkyl; and each R 3 independently is halogen or C 1-6 alkyl; in free base form or in acid addition salt form, for use in the treatment, prevention or delay of progression of dyskinesia associated with dopamine agonist therapy in Parkinson's Disease.